The present invention relates to the technical field of surgical dressings and adhesive compositions for surgical dressings or skin-adhering devices such as ostomy products, mammary prostheses or any alternative product to be fixated to a skin surface part of a patient or person.
Numerous adhesive compositions known as hydrocolloid compositions or materials are known, e.g. from U.S. Pat. Nos. 3,339,546, 4,192,785, 4,296,745, 4,367,732, 4,813,942, 4,231,369, 4,551,490, 4,296,745, 4,793,337, 4,738,257, 4,867,748, and 5,059,169, to which reference is made and which are hereby incorporated in the present specification by reference.
Conventional hydrocolloid material-containing adhesive compositions comprise a particulate hydrocolloid material such as gelatine, carboxymethylcellulose, and pectin, or mixtures thereof, and a binder or adhesive component which is mixed with the hydrocolloid material in an intimate composition of particulate material in which, following hydration of the hydrocolloid material, the adhesive component constitutes droplets providing adhesion to the skin surface part of the patient or person to whom the surgical dressing or other skin-adhering device is to be adhered by means of the adhesive composition.
It has been realized that the hydrocolloid material-containing adhesive composition has to fulfill certain requirements as to flexibility and cohesion in order to, on the one had render it possible to shape the adhesive composition in conformity with the skin surface part of the patient or person to which skin surface part of the surgical dressing or the skin-adhering device is to be fixated and further to allow any adaptation to changes of the shape of the skin surface part in question and, on the other hand, for preventing components of the adhesive composition, particularly the tacky adhesive component itself, from becoming separated from the major body of the adhesive composition and eventually left at the skin surface part of the patient or person as the surgical dressing or the skin-adhering device is removed from the skin surface part in question.
Where the adhesive composition is part of an-adhesive surgical dressing for the treatment of wounds, such as bed sore or pressure sore, the hydrocolloid material-containing adhesive composition further has to exhibit a high liquid- or water-absorbing capability.
In the present context, the term "liquid" means any water-based liquid such as any body fluid, e.g. blood or blood-containing biological liquid, or simply water.
An object of the present invention is to provide an adhesive surgical dressing fulfilling the above requirements as to high flexibility, high cohesion, and high liquid-absorbing capability.
A further object of the present invention is to provide a high flexibility, high cohesion, and high liquid-absorbing adhesive composition for an adhesive surgical dressing, including a skin-adhering device such as an ostomy product, a mammary prosthesis or similar skin-adhering appliance.
A particular advantage of the present invention relates to the fact that the adhesive composition according to the present invention and constituting the adhesive composition of the adhesive surgical dressing according to the present invention exhibits a liquid-absorbing capability in excess of 3 times the weight of the adhesive composition, such as a liquid-absorbing capability of the order of 6-20 times the weight of the adhesive composition, while maintaining its integrity even when highly hydrated, so that such hydrated composition may thereafter be removed substantially intact from a wound and/or from the skin with little if any of the tacky adhesive component remaining as a residue in the wound or on the skin.
A particular feature of the present invention relates to the fact that the adhesive composition according to the present invention and constituting the adhesive composition of the adhesive surgical dressing according to the present invention is easily produced from conventional constituents which in accordance with a novel and surprising realization provides a highly advantageous adhesive composition and highly advantageous adhesive surgical dressing, respectively, exhibiting high flexibility, high cohesion or physical integrity, and a high liquid-absorbing capability.
The above objects, the above advantage, and the above feature together with numerous other objects, advantages, and features which will be evident from the below specification are obtained by means of an adhesive surgical dressing comprising:
a backing layer defining opposite first and second side surfaces, and PA1 a adhesive composition applied to said first side surface of said backing layer, said adhesive composition comprising: PA1 filaments of a substantially elongated configuration, said adhesive material having a strong affinity and providing a surface-coating for said filaments, said filaments and said backing layer being to no substantial extent soluble in said adhesive material, said adhesive-coated filaments defining a three-dimensional mesh structure or network bonded together by said surface-coating of said filaments, and said hydrocolloid material being retained within said mesh structure and being swellable within said mesh structure upon exposure to and absorption of liquid. PA1 a non-toxic and water-insoluble tacky adhesive material, PA1 a water absorbing and swellable hydrocolloid material, and PA1 a multiplicity of randomly-oriented polymeric filaments coated by said adhesive material and secured together at points of intersection by said adhesive material to define a three-dimensional open-mesh network, said hydrocolloid material being retained within said mesh network and being expandable within the openings of said mesh network through the absorption of aqueous liquid.
a tacky, non-toxic and water-insoluble adhesive material, PA2 a hydrocolloid material, and
It is believed that the adhesive composition of the adhesive surgical dressing according to the present invention acts as a highly-absorbent sponge that resists disintegration and the release of objectionable residue, although the below explanation of the function and operation of the adhesive composition is by no means to be construed as limiting the present invention. It is thus believed that the mesh structure constituted by the filaments which are bonded together through the surface-coating of the filaments provides a sponge network in which the hydrocolloid material, which in an aqueous environment becomes a gel, is retained. As the hydrocolloid particles swell upon exposure to and absorption of water, the cells or interstices of the sponge defined by the mesh structure become enlarged but still remain intact because of the integrity of the filaments which are joined together through the adhesive surface-coating of the filaments.
According to the preferred embodiment of the adhesive surgical dressing according to the present invention, the mesh structure is expandable as the water-swellable hydrocolloid material expands through the absorption of liquid. Thus, the filaments of the mesh structure are in accordance with the preferred embodiment of the adhesive surgical dressing adapted to allow some deformation or rearrangement of the filaments of the three-dimensional mesh structure, still providing a high integrity of the adhesive composition of the adhesive surgical dressing.
The adhesive surgical dressing according to the present invention further preferably exhibits a high liquid-absorbing capability as the adhesive composition is capable of absorbing an amount of water equal to at least 3-6 times the weight of the adhesive composition, preferably an amount of water equal to 6-12 times the weight of the adhesive composition.
It is believed that numerous materials may be used for the flexible, elongated filaments of the adhesive composition which interconnect to provide the three dimensional mesh structure characteristic of the present invention, such as polyethylene, polyesters, polyurethane, or polypropylene. Polyethylene has been found particularly effective but other tough, flexible polymeric materials having similar properties and having an affinity for the adhesive material that coats and joins such filaments together in an open-mesh network are believed suitable.
In accordance with the teachings of the present invention, the filaments may be surface-treated for providing or enhancing such affinity for the adhesive material, e.g. be plasma- or corona-treated or surface-coated by an affinity-promoting agent, such as a binder or adhesive material. Furthermore, the filaments or fibers have to be of adequate strength for providing a three-dimensional mesh structure of adequate strength which may stand the forces which are induced into the mesh structure through the expansion of the hydrocolloid material retained within the mesh structure.
It is believed that the filaments have to constitute a specific minimum amount of the adhesive composition in order to provide an integral mesh structure. Dependent on the filaments, the adhesive material, and the hydrocolloid material in question and further in particular the densities of the materials in question, the filaments are believed to constitute no less than approximately 3%, and preferably no less than approximately 5% by weight of the adhesive composition, in order to provide adequate and sufficient filament material for defining the three-dimensional mesh structure.
The filaments or fibers of the adhesive composition of the adhesive surgical dressing according to the present invention may be made from separate filaments or separate fibers, or alternatively be produced from a film which in accordance with a particular production technique is shredded into elongated filaments. The filaments of the adhesive material of the adhesive surgical dressing according to the present invention are preferably made from a film (or foil) of a thickness of 20-200 .mu.m, such as 20-100 .mu.m, preferably 25-50 .mu.m, defining a major dimension, which major dimension is of the order of 0.5-100 mm, such as 1-10 mm, preferably 1-6 mm. In the present context, the term "major dimension" means a dimension along a predominant direction of a filament in question, as different from e.g. a diameter of sphere. The filaments exhibit a major dimension and further a minor dimension or minor dimensions orientated perpendicularly to the major dimensions.
Alternatively, the filaments may constitute fibers defining a length and a diameter, which length and which diameter are of the order of 5-100 mm and 5-50 .mu.m, respectively, such as 6-60 mm and 10-30 .mu.m, respectively, preferably approx. 3-40 mm and approx. 21 .mu.m (3.3 dTex), respectively. The tacky adhesive material of the adhesive composition of an adhesive surgical dressing embodying the present invention may be made from any of numerous viscous, water-insoluble gum-like materials such as polyisobutylene, silicone rubbers, polyurethane rubber, sucrose acetate isobutylate, acrylonitrile rubber, butyl rubber, natural or synthetic gum or rubber-like materials optionally in combination with plasticizers, tackifiers or solvents enhancing the adhesive characteristics of said materials, or mixtures thereof.
The hydrocolloid material of the adhesive composition of the adhesive surgical dressing according to the present invention may constitute a water-absorbing and/or water-swellable material such as carboxymethylcellulose, carboxymethyl starches, and alkali metal derivatives thereof, alginates, polyvinyl alcohol, carrageenan, gelatine, citrus pectin, powdered pectin, synthetic or natural gums, such as gum guar, gum arabic, locust bean gum, karaya, or mixtures thereof.
The hydrocolloid material may be a liquid or a solid material but would normally be present in the adhesive composition in particulate or finely divided form. When the hydrocolloid material is exposed to aqueous liquid, such hydrocolloid material swells and provides in most instances a gel which is retained within the three-dimensional mesh structure defined by the filaments of the adhesive composition.
The backing layer of the adhesive surgical dressing according to the present invention may be made from a water-and/or air-permeable material, or alternatively a water-and/or air-impermeable material, or a combination of such materials, e.g. a laminated structure including permeable and impermeable materials. The adhesive composition may be adhered through its adhesive component to the backing layer and, alternatively, may be adhered to the backing layer through a tie layer constituted by a glue layer or an adhesive layer, such as an acrylic binder layer.
The backing layer may be made from any appropriate plastic film material such as polyurethane, polyethylene, polypropylene, styrene-isoprene copolymers, styrene-butadiene block copolymers, butadiene rubbers, isoprene rubbers, neoprene rubbers, acrylonitrile rubbers, silicone rubbers, butyl rubbers, chloroprene rubbers, polyvinylchloride, polyamides, or mixtures thereof, although an elastomeric backing composed of a thin, stretchable film of polyurethane or similar material is preferred.
According to preferred embodiments of the adhesive surgical dressing, the adhesive composition comprises polyisobutylene in an amount of 30-56%, such as 40-60%, e.g. or preferably 42%, 44% or 60%, by weight of said adhesive composition.
According to preferred embodiments of the adhesive surgical dressing according to the present invention, the adhesive composition comprises particles of hydrocolloid material composed of gelatine, carboxymethyl cellulose and pectin in a total amount of 8-65%, such as 35-50%, e.g. or preferably 48% or 25% by weight of said adhesive composition.
According to preferred embodiments of the adhesive surgical dressing according to the present invention, the adhesive composition comprises filaments made from polyethylene in an amount of 3-25%, such as 5-15%, e.g. or preferably 10%, 8% or 15%, respectively, by weight of said adhesive composition.
The above objects, the above advantage, and the above feature, together with numerous other objects, advantages, and features which will be evident from the present specification, are obtained by means of an adhesive composition for the fixation of an ostomy product or similar product to a skin surface part of a patient or person, said adhesive composition comprising:
The adhesive composition according to the present invention, may advantageously comprise any of the characteristics of the adhesive composition of the adhesive surgical dressing according to the present invention.